This movie is credited with creating the "aluminum foil hat" for paranoid conspiracy people.
Writer and director Marshall Brickman used in this movie the story mechanism whereby the lead male character converses and gets advice from the ghost of Sigmund Freud. This type of device was used in Play It Again, Sam (1972), where Woody Allen liaised and talked with the ghost of Humphrey Bogart. Brickman co-wrote several movies with Allen during the 1970s.